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British Journal of Oral and Maxillofacial Surgery 53 (2015) 760–762
Short communication
Emerging developments in the use of bioactive glass for reconstruction of craniofacial bone A.C. Profeta a,b a b
King’s College Hospital NHS Foundation Trust, Department of Oral and Maxillofacial Surgery, Denmark Hill, London SE5 9RS, UK Friedrich-Schiller-University Jena, Otto Schott Institute of Materials Research (OSIM), Fraunhoferstr. 6, D-07743 Jena, Germany
Accepted 21 April 2015 Available online 6 June 2015
Abstract For decades, researchers have investigated the use of bioactive glasses as synthetic substitutes for bone grafts that can bond with bone, and recent discoveries have shown that their clinical performance in osteoplastic and reconstructive surgery has exceeded that of traditional synthetic materials. Craniofacial reconstructions with bioactive glass were associated with good functional and aesthetic results with no donorsite morbidity, and the material’s unique ability to inhibit bacterial growth was advantageous when used in dead spaces that were chronically infected. Treatment of large defects in the head and neck with these multifunctional biomaterials is a suitable alternative to conventional methods. © 2015 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
Keywords: Bioactive glass; Alloplastic grafting materials; Osteoplastic and reconstructive surgery
Introduction
Reconstruction of the cranial vault
Hench et al reported the first bioactive glass in 1971.1 It dissolves at a similar rate to that at which new host tissue is remodelled, and because of its osteogenic properties, serves as a biocompatible interface along which bone cells migrate.1 Notably, its constituents are physiological chemicals found in the body, typically silicium, sodium, potassium, magnesium, oxygen, calcium, and phosphorus. According to several studies, the chemicals never rise to concentrations that could affect adjacent tissues and they provide appreciable antibacterial properties.1 Bioactive glass, also known as 45S5, and its various products have been used widely in the reconstruction of craniofacial bone.
Earlier studies have reported the use of 45S5 particles mixed with particles of autologous bone as an adjunct to reconstruction of the cranial vault.2 On follow-up, computed tomography (CT) showed that most of the reconstructed defect had been converted to bone within 6 months. At 4 years it was stable and there was no need for another operation or biopsy examination. A promising new development in calvarial and midface reconstructions has been the use of customised porous implants made of a supporting framework of fibre-reinforced composites (FRC)3 or polymethylmethacrylate (PMMA)4 with a modified formula of bioactive glass (S53P4), which combines the workability of the resinous materials with the innate bioactive and antimicrobial properties of the latter (Figs. 1 and 2). In longitudinal examinations with follow-up of 43 and 5 years,4 wound healing progressed normally and clinical postoperative symptoms gradually diminished. Each custom-made implant remained in its original position and provided the expected functional
E-mail addresses: andrea.profeta@kcl.ac.uk, andrea.profeta@uni-jena.de
http://dx.doi.org/10.1016/j.bjoms.2015.04.019 0266-4356/© 2015 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
A.C. Profeta / British Journal of Oral and Maxillofacial Surgery 53 (2015) 760–762
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Fig. 1. Tailor-made polymethylmethacrylate (PMMA) and bioactive glass (S53P4) implant before operation. Reproduced with permission.
Fig. 3. Computed tomogram of a left temporal bony defect 2 years after reconstruction. White arrows show new bone between the implant and surrounding bone. Reproduced with permission.
Fig. 2. Implant adjusted to its correct position in the skull. Reproduced with permission.
and aesthetic outcome. There were no long-term complications such as implant-induced resorption of the skull, late inflammatory reactions, or acute systemic toxicity. The perforated structure of the implants favoured the ingrowth of tissue, and provided solid flexural modulus and mechanical strength. The bioactive coating was regarded as the key attribute, particularly in patients who had previously had reconstruction material removed because of infection.3 Finally, the synthetic implants did not give rise to artifacts in postoperative imaging for follow-up of the tumour (Fig. 3).3,4
Reconstruction of the facial skeleton S53P4 granules moistened with saline have been used successfully to restore the contour of the facial skeleton and reconstruct the frontal bone with no complications or evidence of resorption.5 Tailor-made rigid plates manufactured from S53P4 have been used to repair fractures of the orbital floor, and the use of plates to reconstruct defects in the orbital wall after resection of fronto-orbital tumours has maintained the position of the globe during follow-up.6 Without exception, the materials were tolerated well, and functional and
aesthetic outcomes were good. S53P4 is the only material used in orbital reconstruction that has antibacterial properties, which may be the reason why no acute or late infections were reported.6 In histological studies, special attention was paid to the formation of new bone and attachment to host tissues. Although S53P4 biodegrades slowly, the plates were firmly attached to the orbital bone when histological samples were harvested, which showed that they were firm and incorporated without fixation with screws.6
Paranasal sinus surgery Results have been favourable after use of S53P4 in patients with chronically infected perforations of the nasal septum7 and after canal wall down mastoidectomy.8 In a 5-year clinical follow-up study, Peltola et al reported uneventful outcomes, and formation of bone with no loss of volume in obliterated frontal sinuses over a 10-year period.9 They described the long-term histological healing process and showed formation of histologically normal bone and no inflammatory changes or foreign-body reactions. After use of composite grafts of S53P4 with autologous bone to raise the floor of the maxillary sinus, healing was faster than after use of a bone graft alone (6 months compared with 12 months, respectively).10 These findings further support the premise that the antimicrobial properties of bioactive glass act against pathogens in the sinuses and might help to resolve inflammatory responses and provide favourable conditions for healing.
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A.C. Profeta / British Journal of Oral and Maxillofacial Surgery 53 (2015) 760–762
Conflict of interest We have no conflicts of interest.
Ethics statement/confirmation of patient permission I have received permission to use 2 pictures from Plast Reconstr Surg 2007;120:1963–72, and have had permission to adapt 3 pictures from Eur Arch Otorhinolaryngol 2012;269: 623–8.
References 1. Jones JR. Review of bioactive glass: from Hench to hybrids. Acta Biomater 2013;9:4457–86. 2. Gosain AK. Plastic Surgery Educational Foundation DATA Committee. Biomaterials for reconstruction of the cranial vault. Plast Reconstr Surg 2005;116:663–6.
3. Aitasalo KM, Piitulainen JM, Rekola J, et al. Craniofacial bone reconstruction with bioactive fiber-reinforced composite implant. Head Neck 2014;36:722–8. 4. Peltola MJ, Vallittu PK, Vuorinen V, et al. Novel composite implant in craniofacial bone reconstruction. Eur Arch Otorhinolaryngol 2012;269:623–8. 5. Kinnunen I, Aitasalo K, Pöllönen M, et al. Reconstruction of orbital floor fractures using bioactive glass. J Craniomaxillofac Surg 2000;28:229–34. 6. Peltola M, Kinnunen I, Aitasalo K. Reconstruction of orbital wall defects with bioactive glass plates. J Oral Maxillofac Surg 2008;66:639–46. 7. Stoor P, Grénman R. Bioactive glass and turbinate flaps in the repair of nasal septal perforations. Ann Otol Rhinol Laryngol 2004;113:655–61. 8. Della Santina CC, Lee SC. Ceravital reconstruction of canal wall down mastoidectomy: long-term results. Arch Otolaryngol Head Neck Surg 2006;132:617–23. 9. Peltola M, Aitasalo K, Suonpää J, et al. Bioactive glass S53P4 in frontal sinus obliteration: a long-term clinical experience. Head Neck 2006;28:834–41. 10. Tadjoedin ES, de Lange GL, Holzmann PJ, et al. Histological observations on biopsies harvested following sinus floor elevation using a bioactive glass material of narrow size range. Clin Oral Implants Res 2000;11:334–44.